Various devices have been used to submerge metal scrap in molten metal. A scrap submerging device can be used in a melting system for converting scrap metal into metal ingots. Molten metal contained in a hearth is circulated by a pump contained in a pump well. In one design, molten metal is drawn from the hearth by the pump and circulated from the pump well to a scrap charging well, to a dross well and back to the hearth. Scrap metal such as aluminum can scrap is added to molten metal in the charge well. It is important to facilitate rapid melting of the scrap, but this is difficult to do because the scrap has a low density causing it to float.
Some devices have mechanical equipment located above a charge well that physically submerges the scrap in the molten metal. Other devices utilize a rotor in the scrap charging vessel to pull the scrap into the molten metal. Yet other devices utilize a pump located outside of the charge well that pumps molten metal into a vessel contained by the charge well without the need for mechanical equipment in the charge well itself.
U.S. Pat. No. 6,217,823 discloses using a ramp to achieve a vortex with an initially upward flow of molten metal along a ramp adjacent outer walls inside the scrap charging vessel and then downwardly toward an outlet of the vessel.
One of the disadvantages of current vortexer apparatuses in which molten metal is pumped into the charge well from a pump without any movable parts in the charge well, is that the only way to adjust the level of the vortex is to adjust the speed at which the pump rotates the impeller. This variation of the vortex can be limited by the pumping capacity of the pumps, being either too large or too small to achieve the intended vortex height. In addition, adjusting the height of the vortex by increasing the speed of rotation of the impeller in the base of a pump is disadvantageous because it requires more energy to operate the pump when a higher vortex is desired.